Hair curlers



IDSC. l0, 1968 W H, 1 BRQCK ET AL 3,415,254

HAIR CURLERS 5 Sheets-Sheet 1 Filed July 5, 1966 Dec. l0, 19618 W, H J, BROCK ET AL 3,415,254

HAIR CURLERS Filed July 5, 1966 3 Sheets-Sheet 2 a1f- EI-m 33 I;

:i1- 1s 334? -L3 FIG!o F165 FIGB Dec. 10, 1968 w, H, J, BROCK ET AL 3,45254 HAIR CURLERS Filed July 5, 1966 3 Sheets-Sheet 3 United States Patent O HAIR 'CURLERS William Hudson James Brock and William George Turriff,

London, England, assignorsl to George E. Taylor &

Company Limited, London, England Filed July 5, 1966, Ser. No. 562,879 Claims priority, application Great Britain, July 5, 1965,

7 Claims. (Cl. 132-33) This invention relates to hair curlers of the kind which comprise generally cylindrical formers adapted to be heated before use by placing them on stems of a heating appliance including electrical or other heating means.

It is important that the temperature to which the curlers are heated shall be fairly` closely determined, and with a View to achieving this result, it has been proposed to provide thermostatic control of the heating means, or to provide temperature indicators on the curlers which, for example, change colour when a chosen temperature is reached.

Thermostatic control has not been found to give sutliciently accurate control in many cases, and with colour change temperature indicators/the change of colour is frequently not sufficiently distinctive to provide an accurate indication.

It is the object of the present invention to provide an improved arrangement for controlling the temperature to which the curlers are heated.

According to the invention, a hair curler comprising a generally cylindrical tubular former, in combination with heating means for said curler, said heating means including a stem on which the curler is litted for heating, is characterised in that a latch is provided to retain the curler in `a predetermined position on the stem against the action of a force tending to move it axially relative to the stem, the latch including or being controlled by a bi-metallic element the heat-induced deformation of which, when a predetermined temperature is reached, releases the latch and permits the curler to be displaced from the predetermined position.

Further, according to the invention in a hair curler comprising a generally cylindrical tubular former, the said hair curler is provided with a latch member adapted to engage a retaining surface on a stem of a heating appliance, a bi-metallic elementassociated with the latch being deformed by heat applied to the curler to cause the said latch to be released when a predetermined temperature is reached to permit the curler to be displaced by a force tending to move it axially relative to the stem.

Resilient means may be provided to produce the force tending to move the curler axially on the stem alternatively, the stern may be so positioned that the curler, when released, slides off it under the influence of gravity. The invention is hereinafter described with reference to the accompanying drawings, in which:

FIGURE 1 is a plan view of a heating means for hair curlers showing a number of hair curlers mounted thereon;

FIGURE 2 is a sectional elevation the section being taken on the line 2-2 of FIGURE l;

FIGURE 3 is a cross-section through a hair curler on the line 3-3 of FIGURE 2',

FIGURE 4 is a sectional elevation similar to part of FIGURE 2 showing a hair curler in the position it assumes when the latch is released;

FIGURE 5 is a sectional elevation similar to part of FIGURE 2 showing a :modicatiom FIGURE 6 is a sectional elevation similar to FIG- URE 4, showing the relative positions of the stem and hair curler of FIGURE 4 after the latch has become released;

FIGURE 7 is a detail View showing another modification; and

FIGURE 8 is a side elevation of a heating means in which the hair curlers move under the inuence of gravity when the latches are released.

Referring to FIGURES l to 4 of the drawings an electrical heating means for the hair curlers comprises a hollow base 10 consisting of upper and lower part 11 and 12 having side walls 13 and 14 which abut each other in substantially the mid-plane of the said base. A metal plate 15 located just below the top wall of the upper part 11 of the base has txedly mounted on it a plurality of `metal stems 16 of different diameters, which project outwardly through holes in the top wall of the base. At least the stems of larger diameter may be hollow as in the case of the stern 16 shown in section in FIGURE 2.

An electrical heating element .17, in the form of a length of llat metal ribbon disposed between sheets of mica or other electrically insulating material (such as is commonly used in electric smoothing irons) is mounted between the underside of the plate 15 and a clamping plate 18, the plate 15, heating element 17 and clamping plate 18 being held in position by nuts 19 mounted on screw-threaded studs 21 mounted in internal bosses 22 in the base part 11. One of the nuts 19 also serves to retain on one of the studs 21 an insulating block 23 carrying a heat-sensitive switch 24 one contact 25 of which is mounted on a bi-metal member 26 which, when a predetermined temperature is reached, defonms in such a way as to open the contacts. Suitable conductors 27 connect the heating element 17 and switch 24 in series between two binding posts, one of which is shown at 28, to which also are attached conductors, indicated at 29, for connecting the heating means to a source of electric current. The lower part 12 of the base 10 is held in position on the upper part 11 by further nuts 30 on the studs 21.

The hair curlers 31, of which one is shown in longitudinal section in FIGURES 2 and 4, and in cross-section in FIGURE 3, each comprise an external tube 32, closed at one end, and an internal tube 33 which is tightly tted in the tube 32, and is also closed at one end, the closed ends of the two tubes being at the same end of the curler. The internal tube 33 is slotted longitudinally at 34 and is reduced in external diameter at its closed end, the slot 34 extending at that end up to the point where the diameter is reduced. The slot 34 terminates short of the other end of the tube 33 and is bridged, adjacent that end, by a bridge-piece 35- of less thickness than the tube itself. A shallow groove extends from the end of the slot adjacent the closed end of the tube across the portion of reduced diameter and partway across the outer surface of the end of the tube, and a bi-metallic strip 36, one end of which lies in the groove, is held in position by a ring 37 pressed on to the reduced portion of the tube. The other end of the bi-metallic strip extends over the bridgepiece 35, and is bent inwardly at right angles to form a latch 38 which normally protrudes into the bore of the tube 33, the strip 36 being initially set so that it bears against the bridge-piece 35 when cold. Heat applied to the curler causes the bi-metallic strip 36 to deform in such a manner as to move the latch 38 outwardly. Each stem 16 is formed, near its lower end, with a circumferential groove 39 the upper side wall of which provides a surface to be engaged by the latch 38 when a curler is placed on the stem. A short tapered portion 40 at the upper end of each stem facilitates its entry into the bore of a curler.

A spirally coiled compression spring 41 is mounted in closed end of each curler 31 and, when a curler is placed on a stem 16 so that the latch 38 engages the groove 39, the spring 41 bears on the upper end of the stern and is compressed to produce a force tending to move the curler upwardly relative to the stem, such movement being prevented by the latch 38. It will be apparent that, when the curler is heated, the bi-metallic strip 36 will be deformed to move the latch 38 outwardly, and, at a temperature depending on the setting of the bi-metallic strip 36, the latch will move out of the groove 39, allowing the spring 41 to urge the curler 31 upwardly to the position shown in FIGURE 4.

It will be evident that movement of a curler upwardly in this manner provides a very clear indication that it has reached the required temperature, and it has been found that the bi-metallic strips can ybe set to release the curlers at a fairly closely controlled temperature.

As shown in FIGURES 5 and 6, stems 42 tapered over substantially their whole length may be used instead of the cylindrical stems 16, the internal tubes 33 of the curlers 31 being similarly tapered internally as shown at 43. With this arrangement, as is clearly shown by a comparison of FIGURES 5 and 6, the curlers, when lifted after release of the latches have a greater annular gap between themselves and the stems, with the result that the transmission of heat to them from the stems is reduced, and even if they are not removed immediately after lifting their temperature is not rapidly increased. By suitable selection of the angle of taper, the rate of heat transmission after the curlers have been lifted may be brought to a value such that the further heat received by the said curlers just balances the heat loss from them, so that their temperature remains substantially at the desired value.

The springs for lifting the curlers, instead of being mounted inside the said curlers, may be mounted on the heating means around the bases of the stems. For example, as shown in FIGURE 7 a spiral spring 44 may be mounted around the lower end of each stem 16 to act on the lower end of a curler 31 litted on that stem, the spring being located co-axially around the stem by an annular rib 45 on the base part 11.

FIGURE 8 shows a modified arrangment of the heating means for the curlers, in which the said curlers, when the latches are released, can drop olf the stems under the influence of gravity, thus dispersing with the need for springs. A heating unit 46, similar to that shown in FIG- URES l and 2 is mounted in an inverted position on a support 47 carried by a base 48, so that the stems 16 extend downwardly towards the said base. A tray 4 9 is mounted on the base to receive the curlers 31 when the latches 38 are released, the latches being of the form already described.

The latches, if formed by inwardly bent ends of the bimetallic strips 36, may have a covering of plastics material having very low friction characteristics. Alternatively, they may be formed by studs of such plastics material secured to the said strips, the bent ends then being omitted.

The bi-metallic strips, instead of being mounted on the curlers, may be mounted on the heater stems so as to cooperate with retaining surfaces, such as the side Walls of circumferential grooves, in the internal surfaces of the curlers.

The internal tubes of the curlers are preferably formed of a plastics material, such as nylon, loaded with a heatretaining material such as glass or metal, as described in our co-pending patent application No. 28,366/65, and the external tubes are provided with projections such as,

4 for example, short spikes 51,*to retain ori'them the" Vstrands of hair which are wrapped round them when in use.

We claim:

1. A hair curler comprising a generally cylindrical tubular former, in combination with heating means for said-curler, said heating means includingl a stem-on which the curler is fitted for heating, a latch on the inner Asurface of the curler cooperating with a groove on 'said stem retaining the curler in a predetermined position on the stern against the action of a force tending to move it axially relative to the stem, the latch comprising a lai-metallic element the heat-induced deformation of which, when a predetermined temperature is reached, releases said latch and permits the curler to be displaced fromA the predetermined position. l

2. A hair curler comprising a generally cylindrical tubular former wherein said hair curler is provided with a latch member; on its inner surface said latch member comprising a lbi-metallic element adapted to engage a groove on a stem of a heating appliance, the latch member being deformed by heat applied to the curler to cause the said latch to be released when a predetermined temperature is reached to permit the curler to be displaced by a force tending to move it axially relative to the stem.

3. A hair curler and heating means according to claim 1, wherein resilient means are provided to produce the force tending to move the curler axially onthe stem.`

4. A hair curler and heating means according to claim 1, wherein the stem is so positioned that the curler, when released, slides off it under the inuence of gravity.

5. A hair curler according to claim 2, wherein a spring attached to the said curler is arranged t0 be loaded by the placing of the curler on the stem of the heating appliance, to provide the force tending to move the said curler axially relative to the stern.

6. A hair curler and heating means according to claim 3, wherein the bore of the hair curler, and the stem of the heating means are both tapered, the direction of the taper being such that the radial clearance between the tapered surfaces increases when the curler moves in the direction in which it is urged by the resilient means.

7. A hair curler according to claim 2, wherein the said hair curler comprises inner and outer tubes and the bimetallic element comprises abi-metallic strip extending longitudinally of the curler, ina slot in the inner tube, the bi-metallic strip being clamped to said inner tube lat one end and having at its other end a radially inwardly extending projection, the arrangement being such that heating of the curler deforms the bi-metallic strip so as to move the projection outwardly.

References Cited UNITED STATES PATENTS 1l/1966 McNair 219--222 LOUIS G. MANCENE, Primary Examiner.

J. W. MITCHELL, Assistant Examiner.

U.S. Cl. XR. 219-222 

1. A HAIR CURLER COMPRISING A GENERALLY CYLINDRICAL TUBULAR FORMER IN COMBINATION WITH HEATING MEANS FOR SAID CURLER, SAID HEATING MEANS INCLUDING A STEM IN WHICH THE CURLER IS FITTED FOR HEATING, A LATCH ON THE INNER SURFACE OF THE CURLER COOPERATING WITH A GROOVE ON SAID STEM RETAINING THE CURLER IN A PREDETERMINED POSITION ON THE STEM AGAINST THE ACTION OF A FORCE TENDING TO MOVE IT AXIALLY RELATIVE TO THE STEM, THE LATCH COMPRISING A BI-METALLIC ELEMENT THE HEAT-INDUCED DEFORMATION OF WHICH, WHEN A PREDETERMINED TEMPERATURE IS REACHED, RELEASES SAID LATCH AND PERMITS THE CURLER TO BE DISPLACED FROM THE PREDETERMINED POSITION. 